The placement of occupancy sensors is key to their proper operation. Sen-
sors can be mounted on walls or ceilings, and the use of multiple sensors can
sometimes provide more accurate detection especially in large or irregularly
shaped areas. Occupancy sensors must be able to detect motion in their
assigned space while ignoring mechanical vibrations and other false signals.
Any malfunctioning of an occupancy sensor can be dangerous, especially if
the area is a stairwell or other location where illumination is important for
safety. Occupancy controls are best used in applications where occupancy does
not follow a set schedule and is not predictable.
Dimmers
Dimmer modules manage low-voltage switch and line voltage output controls
of the dimmer’s lighting loads. Stand-alone dimmers typically have status indi-
cators, analog inputs for photo-cell or occupancy sensors, diagnostics, and are
able to optimize responses for various types of lighting fixtures. Dimmers can
be used for specific spaces such as areas with audio visual presentations or
throughout the total system for managing large facilities (Fig. 4.4).
Figure 4.4 Dimmer.
Lighting Control Systems 53